What will the weather be like tomorrow?

Callie Carmichael, Wochit Correction: A previous version of this story misstated the number of states under red flag warnings. Five states were under Parts of Pennsylvania, New Jersey, Michigan, Washington and Alaska will remain under the warning until 8-10 p.m. local time, the weather service said. In Pennsylvania, lightning strikes may cause fires to start in dry areas. In Washington, dry and unstable air mass with warm temperatures could contribute to a fire. “Be careful with any activities that could potentially lead to a wildfire,” the weather service warned Michigan residents. “Camping, outdoor grills, smoking materials, chain saws and all-terrain vehicles all have the potential to throw a spark and ignite a dangerous and destructive fire.” What is a red flag warning? The weather service issues a “red flag warning” when weather conditions in an area are ripe for the spread of wildfires due to a combination of strong winds, low relative humidity and dry fuels. “Any fires that develop will likely spread quickly,” the weather service said. “Outdoor burning is not recommended.” Wildfires in Canada affecting air quality in US Millions of Americans are exposed to The weather service issued Air pollution increases the risk of Wildfire, smoke map for US, Canada

Tomorrow (Sunday): The most sun shines during morning and midday hours. As south-southwest breezes ramp up with a few 25 mph gusts during the afternoon, increased cloud cover can also be expected. Late day we may see a couple raindrops or a pop-up storm, but chances are very low. High temperatures in the upper 80s to low 90s — perhaps our second 90-degree day of the year downtown — aren’t too bad for June, given that dew points should stay in the comfortable 50s. Overnight, riding in on gusty south winds (as high as 30 mph) we should see an increase in clouds and humidity. We may stay mighty mild, in the upper 60s to low 70s. Perhaps a couple raindrops start moving in before dawn. Can’t rule out one or two rumbles of thunder that may act as an early Monday alarm clock for us.

• News • • All News • Pennsylvania • New Jersey • Delaware • National • World • Health • Entertainment • Politics • Traffic & Transportation • Business • Recalls • Weather • • Latest Weather • Radars • Become a Weather Watcher • Sports • • All Sports • CBS Sports HQ • Eagles • Sixers • Phillies • Flyers • College • High School • Odds • Video • More • • Station Info • Contact Us • Share Photos and Video • Send Us a News Tip • Advertise With Us • Contests & Promotions • Download the CBS Philly App • Photo Galleries • Mentioned On-Air • Jobs & Internships • Log In • • Search • Search • Philly region upgraded to most hazardous air quality As of 9 p.m. Wednesday, the Philadelphia region is in the most hazardous air quality category. It's the worst the air quality has been in the city since 2008. By 11:30 p.m., Philly now has the worst measurable air quality in the world. A good portion of the area was upgraded from a "Code Purple" to a "Code Maroon." It's level six on a six-point scale, which means everyone will be more affected by the air quality. Parts of Allentown in the Lehigh Valley are also in a "Code Maroon," meaning "hazardous" level of air quality, according to AirNow.com The Lehigh Valley ranks as the second the worst air quality out of all measured locations in the United States, per AirNow. Parts of of New Jersey, including Burlington and Ocean Counties, along with Scranton and Wilkes-Barre in Pennsylvania are also among the worst. On Thursday, it could possibly get...